When extracting a tooth, in particular following a non-scheduled extraction or following a trauma, the gaps between the neighbouring teeth are generally filled temporarily with a unit prosthesis fastened with the help of cumbersome hooks, which are bothersome for the patient and visible, or with a bridge, which has the drawback of requiring the reduction of the supporting teeth to allow the realization of a part comprising three teeth. The goal of these temporary elements is to ensure a functional rehabilitation, to improve the aesthetic presentation by filling the toothless gap created by the extraction and to enhance the progress of the bone healing.
The major drawback of the temporary bridges and unit prostheses stems from the fact that these elements cannot be produced in only one work session, which would take place immediately after the extraction. In fact, they must be manufactured by dental-prosthesis technicians working on the base of an impression made by the dentist. These various operations require at least two work sessions for the dentist, between the moment when he extracts the tooth and makes the impression and the moment when he can put the temporary element, which has been manufactured in the meantime by the workshop of the prosthesis-maker, in place in the mouth of the patient. Assuming that the element has been properly manufactured and that it requires no or only little adjusting, the dentist requires at least two sessions of intervention with the patient.
Furthermore, the attached partial prosthesis or the removable unit prosthesis has further drawbacks. It requires a large volume in the mouth, it generates a loss of adaptation as the healing progresses, it has a relatively high mobility and creates aesthetic damage due to the fact that the hooks are visible, which is often considered as a handicap by the patient or the people around him.
The temporary unit bridges require cutting to shape the teeth adjacent to the toothless gap, which is unacceptable when these teeth are healthy. In fact, such a cutting to shape leads to the voluntary mutilation of healthy teeth to allow putting in place a temporary accessory. In addition, this solution is particularly expensive for the patient.
The publication U.S. Pat. No. 4,163,318 describes a device for filling the space between two teeth comprising two extensible arms moved by a central pinion meshing two opposite racks, the central pinion being mobile in rotation in a support by means of a driving screw. This device has the drawback of being invasive, since the ends of the extensible arms are inserted in seats cut in the healthy teeth. It is relatively expensive since it requires accuracy in the micron range. Furthermore, it comprises no mechanical locking means for the arms in extended position that would prevent the risk of loosening or misadjusting of the device. This device is thus not satisfying.